Diestock



JAooBB. HOOVER, or COLUMBUS, oHIo.

DIEsT'ocK.

Specification of Letters Patent.

Patented Nov. 4, 1919.

Application led April 20, 1917. Serial No. 163,397.

cerned with the construction of a die head or holder,- in which the dieitself may be accurately `and perfectly adjusted and held in such a waythat the thread-cutting portions of the die form a perfect circle andproduces a true circular threaded member. Another object of theinvention is the provision of' a simple and convenient adjustment for adie in a holder and also an` equally convenient removal of the colletwhich cooperates Vwith the portions of the die to maintain the memberbeing threaded in position. To the accomplishment of the foregoing andrelated ends, said invention, then,

consists of the means hereinafter fully described and particularlypointed out in the claims.

The annexed drawing and the following description set forth in detailcertain mechi anism embodying the invention, such disclosed meansconstituting, however, but one of various mechanical forms in which theprinciple of the invention may be used.

In said annexed drawings:

Figure 1 is a front elevation showing a die stock constructed inaccordance with my invention; Fig. 2 is a vertical longitudinal sectionthrough `the die holder and die; and Fig. 3 is a transverse centralsection on the line 3-S, Fig. 2, showing the collet.

In Fig. 1 there is shown a die holder 1 having the usual enlarged,circularly apertured center and oppositely extending handles 2. Thecentral portion is split along a vertical line and is Vprovided with twoupwardly extending lugs 3. y These lugs 3 are provided with alinedapertures which are threaded to receive an adjusting screw 4 forcontracting or expanding the size of the die holder l. For convenienceof operation the adjusting screw 4 is provided with a transverseaperture 54 in its head, in which may be received an adjusting lever 6.

The die 15 which is used in the holder 1 is of the type known as asingle one-piece die, which is split transversely and is provided withoppositely beveled corners 7 and 8 at its ends. These oppositely beveledcorners 7 and 8 are so formed with respect to each other that a rightangle is produced thereby. Mounted at one side of the upwardlyextendinglugs 3 is a boss 9, which .is provided with an aperturedirected at right angles to the plane of the right-hand corner7 (asseenin Fig. l). In this thread- Ved aperture in the boss 9 is mounted asimilarly threaded adjusting pin 10, which is providedwith a fiatright-angled end adapted to contact the surface of the corner 7. Uponinward movement the pin 10 `is adapted to force the die 15circumferentially Viny the holderuntil the other corner 8 of the dieengages squarely against the side of the pin 10. Thereafter furthermovement of the adjusting pin opens the die and also forces the lsameinto contact with the die holder. To adjust the die to any desired sizethe die holder is firstopenedslightly by adjustment of the screw 4, andthe die is then expanded by adjustment of the pin 10. When the die hasbeen expanded the amount desired the holder is clamped tightly upon thedie by further adjustment of the screw 4.

I have found that by adjusting first the die to the holder bycircumferential movement and expansion of the die, and then by adjustingthe holder to the die there is no chance for breakage of the die at itsweakened portion opposite to the transverse slit therethrough, andfurthermore the threaded surfaces of the die are so positioned that theyconstitute a perfect circle and will cut perfectly formed threads on thestock.

Referring now to Fig. 3, there is shown in the back of thedie holder l aplate 16 provided with an extension in the form of a sleeve 17, in whichthere is removably mounted a collet 18. The collet 18 is formed with aflange 19 resting against the end of the sleeve, and is held in positionby means of a set screw 20 entering a recess 21 in the collet, thuspermitting the use of collets of different inner size in the samesleeve. On the rear face of the die holder there is formed an interiorlyprojecting liange 22, against which the plate 16 is adapted to rest whenthe sleeve is. engaged in the die holder,

' stated meansA be employed.

and a screw 23 may be used to engage the two flanges with each otherftomaintain the sleeve in position.

'Ihe simplicity of construction and coninvention is not limitedto usehand tools alone, but may be equally useful 4when ap- `pliedto automaticscrew machines.'`

Other modes of applying the prmcipleof my invention `may be employedinstead of the one explained, change being -made as .regardstheimechanisml herein.. disclosed,

provided the means stated -by and of the lfollowing claims or theequivalent of such I therefore particularly point outiland distinctlyclaim as my invention 1. Ina die, lthe, combination of a split,adjustable die -head,ra split .die kmember litting within said head andcircumferentially .movable therein, the ends of said die member beingbeveled outwardly, and an adjusting. pin mounted in said head, saidpinhaving va right angled inner end and being mounted with suchend bearingagainst one Ybeveled end of said die, said] pin being adapted, whenvmoved inwardly, .to initially kmove said.l die circumferentially and toeX- pand the sameupon contact of: such-other beveled end of said .dieagainst'the sides of said ,v p y c. -f 2. n a die, the combination of asplit, ad-

Copies of'thispatentmay b'e obtained'rfor lve cents each,byaddressingthe Commissioner of Patents,

justablevdie head, afsplit die membertting withinsaid head andcircumferentially movable therein, the ends of said die member beingbeveledfoutwardly, and an adjusting pin mounted in said head at an angleto a the otherend of said die and being adapted, upon inward movement,.toexpand the same. 3; In a die the''combinationI of a split adjustabledie head, a split die member within 'said head 'and having outwardlybeveled .ends,an adjusting-,screw mounted Ain said head` andfadaptedtobear against one of such beveled ends, ythe'other beveled end ber ingadapted to vcontact withl the sides of said screw, movement of said'screw being adapt-v ed to expand said dievmember circumferentially insaid head. 4

'radial line therethrough, the inner end ofV said pin engagingllaterally yagainstv one beveled end of said die and forming a bearingtherefor, and said pin engaging against 4c.' In a diethe combination ofa die head said die head andy lmember being split upon radial lines,spaced at1 an acutel 4angle to each other, sothat saidmembervand saidhead will remain approximately concentricv throughout their adjustedpositions;

. Signed by me this 14: dayo April, 191;?. l

JACOB B. HOOVER@ c Washington, I). C. j

